How to create a .NET8 WebAPI for consuming messages from RabbitMQ

1. Pull and run the RabbitMQ Docker container

Install and run Docker Desktop on your machine, if you haven't already

You can download Docker from the following link: https://www.docker.com/products/docker-desktop

Start RabbitMQ in a Docker container by running the following command:

docker run -d --name rabbitmq -p 5672:5672 -p 15672:15672 rabbitmq:3-management

The password is also guest

2. Create a .NET8 WebAPI with VSCode

To create the project, you can use the dotnet new command to create a new Web API project

dotnet new webapi -o RabbitMQWebAPI

3. Load project dependencies

First, you will need to install the RabbitMQ.Client NuGet package in your project

dotnet add package RabbitMQ.Client

This is the csproj file

<Project Sdk="Microsoft.NET.Sdk.Web">

  <PropertyGroup>
    <TargetFramework>net8.0</TargetFramework>
    <Nullable>enable</Nullable>
    <ImplicitUsings>enable</ImplicitUsings>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.AspNetCore.OpenApi" Version="8.0.2" />
    <PackageReference Include="RabbitMQ.Client" Version="6.8.1" />
    <PackageReference Include="Swashbuckle.AspNetCore" Version="6.4.0" />
  </ItemGroup>

</Project>

This is the project files and folders structure

4. Create the Controller

using RabbitMQ.Client;
using RabbitMQ.Client.Events;
using Microsoft.AspNetCore.Mvc;
using System.Text;

namespace RabbitMQWebAPIConsumer.Controllers
{
    [ApiController]
    [Route("[controller]")]
    public class ValuesController : ControllerBase
    {
        private readonly IConnection _connection;

        public ValuesController(IConnection connection)
        {
            _connection = connection;
        }

        [HttpGet]
        public void Get()
        {
            using var channel = _connection.CreateModel();
            channel.QueueDeclare(queue: "hello",
                                 durable: false,
                                 exclusive: false,
                                 autoDelete: false,
                                 arguments: null);

            var consumer = new EventingBasicConsumer(channel);
            consumer.Received += (model, ea) =>
            {
                var body = ea.Body.ToArray();
                var message = Encoding.UTF8.GetString(body);
                Console.WriteLine(" [x] Received {0}", message);
            };
            channel.BasicConsume(queue: "hello",
                                 autoAck: true,
                                 consumer: consumer);
        }
    }
}

5 . Modify the application middleware(program.cs)

using RabbitMQ.Client;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddControllers();

var factory = new ConnectionFactory()
{
    HostName = "localhost",
    UserName = "guest",
    Password = "guest"
};
builder.Services.AddSingleton(factory.CreateConnection());

// Add services to the container.
// Learn more about configuring Swagger/OpenAPI at https://aka.ms/aspnetcore/swashbuckle
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();

var app = builder.Build();

// Configure the HTTP request pipeline.
if (app.Environment.IsDevelopment())
{
    app.UseSwagger();
    app.UseSwaggerUI();
}

app.UseRouting();

app.UseAuthorization();

app.MapControllers();

app.Run();

6. Run and test the application

We have first to run the producer application: https://github.com/luiscoco/RabbitMQ_dotNet8WebAPI_producer

And send a messate from the producer app to RabbitMQ queue "hello"

We run the application with this command

dotnet run

We navigate to the application swagger API doc URL: http://localhost:5044/swagger/index.html

We received a message from RabbitMQ queue "hello"